When Helen Thayer became the first woman to complete a solo expedition to the Magnetic North Pole, she brought along an Inuit dog named Charlie to warn her if polar bears were coming and protect her.

Thayer, an explorer with the National Geographic Society, said she and her husband Bill Thayer later developed an interest in studying wolves in the Canadian Yukon territory. She said they wanted to go get a close look at the wolves’ lifestyle in the wild rather than in captivity, and they realized Charlie might be able to help them.